Earlier quoted context omitted.
This seems like clear "witness intimidation" aka "Tampering with a witness, victim, or an informant" https://www.law.cornell.edu/uscode/text/18/1512 (b)Whoever knowingly uses intimidation, threatens, or corruptly persuades another person, or attempts to do so, or engages in misleading conduct toward another person, with intent to— (1)influence, delay, or prevent the testimony of any person in an official proceeding;…
Cannot prove it unless the victim was in a state that allows one party consent audio recording and was recording audio. Although Florida is the only southern state that requires all party consent for recording audio, and I presume the previous poster was talking about Texas. Smartphones have solved the recording audio problem, so presumably it would have been possible.
Is this true even when gathering evidence of a crime?